1. Field of the Invention
This invention relates to the field of circulation systems for ponds, lakes, municipal tanks, and other bodies of water. It particularly relates to the field of such circulation systems for relatively large and deep bodies of water in which high waves may periodically develop. It also relates to circulation systems for smaller and shallower bodies of water such as in municipal or similar water tanks and containers.
2. Discussion of the Background
One group of improvements of the present invention has particular application to larger and deeper bodies of water that may develop large waves (e.g., 4-6 feet high or more). Circulation systems for such bodies that float on the surface of the water must then rise vertically the height of each wave and often must do so very quickly (e.g., within a few seconds or less). Typical circulation systems have a draft hose attached to a flotation platform floating on the surface. The hose extends downwardly (e.g., 20- 50 feet or more) into the body of water and can have a diameter on the order of 3 feet. In operation, such circulation systems are drawing a large volume of water up the draft hose and as the flotation platform rises with each wave, the attached draft hose must also rise with it.
In many such circulation systems, it is desirable to control the direction and level of the water being drawn into the bottom of the draft hose by providing a horizontal plate or other structure adjacent the inlet to the hose. However, a problem can occur that the large volume of water in the hose cannot quickly escape back out of the restricted bottom or inlet of the hose as it is lifted with a wave. Consequently, great stresses are put on the flotation platform and hose of the system as the flotation platform rises with each wave and attempts to pull up with it the very heavy hose full of water. In extreme cases, the stresses can damage or even destroy the flotation platform as well as the hose and other parts of the system. As indicated above, the primary cause of the problem in such systems is that the column of water in the hose cannot escape fast enough out the restricted bottom of the hose, particularly in high seas with waves cresting at 4-6 feet or more every few second or so.
Larger and deeper bodies of water which may develop high and violent waves can also present problems to the float arrangements for such circulation systems. That is, many systems have floats that are essentially rigidly attached to elongated arms extending outwardly of the central platform of the system. The floats commonly extend downwardly from the ends of the arms and serve to suspend or support the platform via its arms on the surface of the water. Under normal conditions with gentle waves, such float arrangements work fine as there is enough time for the water to move around the floats without exerting any large side forces on the arms. However, when high winds or other elements develop, the waves can become quite high and violent. In these situations, there can be large forces exerted on the floats from the water pushing against them. The side forces on the floats then translate into a twisting force or torque on the elongated arms fixedly attached to them and the platform. This twisting of the float arms can eventually fatigue them to the point of failure. In extreme cases, the side forces may even snap or otherwise damage the arms so they do not support the platform properly atop the water.
Other improvements of the present invention have particular applications to municipal drinking and similar tanks of water. Such tanks or other containers for potable water have special needs and requirements. For example, it is desirable that all of the water in the tank be thoroughly or uniformly mixed so there are essentially no dead spots, including in any corners and along the walls and floor of the tank. Such mixing is preferably accomplished relatively quickly by the circulation system and maintained so over extended periods of operation. It is also desirable that the circulation system be designed to easily and quickly inject disinfectants such as chlorine and chloramines into the circulating water.
With these and other problems and desired characteristics in mind, the adaptations of the present inventions were developed.